For many years, electrically operated fans have been used to ventilate undesirable gases and odors from living quarters of various kinds such as homes, recreational vehicles and residences of various other types. Such fans are particularly useful for rooms such as bathrooms, kitchens, attics, and basements and are used to vent gases and odors to the outside air.
Many different types of venting systems are known such as window mounted fans, door frame mounted fans, roof mounted fans and the like. It is also known that it may be desirable to delay the inactivation of the fan for a period of time after a switch has been turned off. Many types of time delay circuits are available providing for automatic control of the circuit so that lights or fans are turned on or off after a preselected time interval.
Despite the many ventilating systems and time delay switches which are available in the prior art, there is a need for a simple effective timeout exhaust fan system which includes a variable time delay capable of being set by the user and which preferably may be configured for direct replacement of conventional wall mounted switches.